A panel of More Fun Comics #73 (November 1941), featuring Green Arrow and Speedy's debut and their original costumes. Art by George Papp.

The original Speedy's real name was Roy Harper, Jr.. He first appeared in More Fun Comics #73 (November 1941), where he was identified as the orphaned son of Roy Harper, Sr., a forest ranger who had died saving a Navajo medicine chief named "Brave Bow" from a fire. Brave Bow raised the younger Roy himself, training him at archery. Roy Jr. took to this training eagerly, and idolized the archer superhero, Green Arrow. As a teenager, Roy is given the opportunity to perform at an archery competition judged by Green Arrow, where he assists the hero at foiling an attempted burglary, even proving himself to be a faster shot than the hero. Following the death of Brave Bow, Green Arrow asked Roy to serve as his sidekick, an offer Roy readily accepted, taking the name Speedy. Harper became the ward of Green Arrow's alter ego, billionaire Oliver Queen.

Harper also became an early member of the Teen Titans. After the original Titans disbanded, he joined a band called Great Frog and became a drug addict, a first in DC comics, in an award-winning story in Green Lantern #85-86 (Sept. & November 1971), part of a classic, 14-issue run by the writer-artist team of Denny O'Neil and Neal Adams. Roy spent some time in the Suicide Squad before returning to the Titans.

Mia Dearden was introduced in Green Arrow (Vol. 3) #2 in 2001. Mia was a teenaged girl who ran from her home after being abused by her father and fell into child prostitution. Mia was rescued from one of her clients by Oliver Queen, who had just recently returned from the dead. Mia began to secretly train with Connor Hawke in archery and combat. Mia continually petitioned Green Arrow to allow her to serve as his sidekick, but Oliver continually demurred, not wanting to put another youngster at risk. Mia redoubled her efforts and Green Arrow finally allowed her to become the new Speedy. Shortly thereafter, she joined the Teen Titans. She has since left the team.

Speedy (like their mentor) has a wide variety of trick arrows, most famously his punching glove arrow which is capable of knocking out villains. Speedy also has several other arrows ranging from sleeping gas arrows, exploding arrows, and regular arrows.

Along with his excellent archery skills, Speedy has mastered several different types of hand-to-hand combat including judo, kickboxing, and karate.

As Arsenal, Roy Harper displayed proficiency with a greater range of weapons, such as guns, truncheons, and boomerangs. He also became a master of Moo Gi Gong, allowing him to use virtually any handheld object as a makeshift weapon.

There was an Earth-Two version of Speedy who was a member of the Seven Soldiers of Victory and All-Star Squadron in the 1940s along with his mentor Green Arrow. Aside from their origin, having been trained on a mesa top together, their history nearly parallels the history of the Earth-One version up until the point when Speedy and Green Arrow, along with their teammates, were thrown into various periods of time during a battle with the Nebula Man. He and his teammates were later retrieved by the Justice Society and the Justice League in order to assist them in saving Earth-Two from the machinations of their old foe the Iron Hand. Years after returning to the present, Speedy came out of retirement, along with his mentor who died during the Crisis on Infinite Earths. This Speedy has not been seen since this time.

Speedy (Mia Dearden) appeared in Season 9 of Smallville in the episode "Crossfire". This Speedy is the Smallville version of Green Arrow's apprentice, Mia Dearden, played by Elise Gatien.[3] She is a prostitute who has trained herself in street-fighting and is attempting to raise enough money to get away from her pimp, Rick. Oliver Queen sees her as a kindred spirit and takes her in to train her while teaching her how to overcome her anger. Rick forces her to lure Oliver to a remote location so he can kidnap him, but Mia turns against him. Rick is arrested, and Mia continues to partner with Oliver, discovering that he is Green Arrow.

In The CW's Arrow, Oliver Queen's sister, Thea Dearden Queen (Willa Holland) is nicknamed 'Speedy" by Oliver (Stephen Amell). Thea starts off as a party lover who is often criticized by Oliver for her actions, and she even winds up in a car accident and is forced to do community service with Laurel Lance (Katie Cassidy). She meets Roy Harper, a thief, when he steals her bag but becomes attracted to him and eventually starts dating him. In season 2, she is still with Roy and runs Oliver's club while being excluded with everyone keeping secrets from her. She later learns that Malcolm Merlyn, the first season's main villain, is her biological father. Thea finds out all of these secrets, except for Oliver's. In the season finale, when she is attacked by Deathstroke/Slade Wilson's minions, Malcolm returns to save her and convinces her to leave Starling City with him. It is also implied that she may change her name. In episode 13 of season 3, "Canaries," Oliver reveals to her that he is the Arrow, and she leaves at the end of the episode for the island Oliver had been stranded on for years to train with him under Malcolm Merlyn's orders.

Colton Haynes appears as Roy Harper / Arsenal on the series as a love interest for Thea. Roy is at one point seeking the "Vigilante", but by the end of the first season has had little success. In Season 2, Roy has come to the attention of the Hood whilst trying to emulate the vigilante's successes in combating crime in Starling City. The Hood employs Roy to act as his intelligence man on the ground in the Glades, and provides a way of communication (a small red arrow that the Arrow used in season 1 to save Roy Harper's life). After the Hood (a.k.a. the Arrow) shoots an arrow through Roy's leg to prevent him investigating the Mirakuru serum being used in Starling City, Roy continues investigating and is subsequently kidnapped and injected with the same serum by Brother Blood. Unable to control his new-found physical powers, Roy nearly kills a man. After finding this out, the Arrow successfully offers to train him. Eventually the Arrow is forced to reveal his identity as Oliver Queen, Thea's older brother, to Roy in an attempt to get him to help stop a second undertaking. The Arrow refers to Roy as "Speedy" when out fighting crime as a way to remind him of Thea and their love, and to control his powers. Roy loses control and goes on a rampage through the city and even kills a man until Oliver manages to get him sedated. After he is sedated for weeks Oliver eventually finds a cure and injects him with it which cancels out the Mirakuru effects. Roy later meets up with Thea and promises that they will leave Starling together forever but first takes part in the attack against Slade Wilson's army and finally donning a red mask and red arrow. In season 3 episode 6, "Guilty", Oliver suggests the name Arsenal, which Roy uses in future episodes.

In the season 3 episode 18, "Public Enemy", when Captain Lance issues an arrest warrant for the Arrow, who he knows is Oliver Queen, Roy dresses up and claims that he is the Arrow, in order to save Oliver. In the following episode, "Broken Arrow", Roy fakes his death, but is unable to tell Thea before he leaves. In season 3 episodes 21 and 22, "Al Sah-him" and "This is Your Sword", respectively, Thea shoots an arrow at Oliver (now Al Sah-him) in order to stop him from killing Diggle. She later learns from Felicity about how Roy faked his death, and goes to his current hideout to meet him, where Roy has taken up a new identity. While she stays with him for one night, as well as give him his Arsenal jacket, Roy leaves the following day, with a letter to Thea. In the letter, he says that he doesn't want Thea to give up her life for him, who will now have to be on the run. He also gives Thea the jacket back, saying that red is more of her color, allowing her to become the new crime-fighter Speedy in the season finale "My Name is Oliver Queen".

Speedy's first animated appearance was in the Teen Titans segments in The Superman/Aquaman Hour of Adventure. In those episodes, Speedy serves in the effective place of Robin.

Speedy has appeared on the Teen Titansanimated series, where he is voiced by Mike Erwin. Although his real name is not given, his appearance is clearly based on that of Roy Harper. He is described as employing "a veritable arsenal" of arrows, in a nod to his future persona. While not a member of the main Titans team himself, he appeared as a supporting character in the episode "Winner Take All", and fought Robin, trying to convince him if winning is really that important. Speedy later joined up with the team's sister group, Titans East. As depicted in the series, Speedy is serious and businesslike as in his Arsenal years in comics, leading Beast Boy to comment on his similarities to Robin. However, when he reappears in "Titans East Pt. 1", more of his traditional bad-boy Speedy personality is seen, as he refuses to apologize for buying fish tacos, which offends Aqualad that the tacos might be his fish friends. He was mind-controlled by Brother Blood in "Titans East Pt. 2" but saved by the Teen Titans. Speedy's bow was broken by Cheshire in "Calling All Titans" when she overpowered him. However, in the episode "Titans Together", Speedy somehow regained possession of his bow when he was freed from his suspended animation. In the end of the Episode of "Titans Together" he was seen with the other titans standing on a building to battle Dr. Light.

Speedy appears in the Justice League Unlimited episode "Patriot Act". Speedy clearly states that he is Green Arrow's "ex-partner", and is visually designed as a slightly older, better built version of his Teen Titans incarnation - his costume is the same; he is voiced by Mike Erwin here as well. Speedy is also featured in issue 30 of the Justice League Unlimited comic book in which he and Booster Gold have to protect the watchtower from Doctor Polaris.

Speedy appeared in the Batman: The Brave and the Bold episode "Dawn of the Deadman!", voiced by Jason Marsden.[4] In the episode, Speedy serves as Green Arrow's sidekick, and is possessed by both Deadman and the spirit of Batman, in order to recruit him and Green Arrow into a battle against the undead army raised by Gentleman Ghost. In "Sidekicks Assemble!", Speedy teams up with fellow sidekicks Aqualad and Robin to battle Ra's al Ghul. This version of Speedy differs greatly from the comics, in which he is more sweet and less confrontational than Robin or even Aqualad.

Roy Harper is a major character in the Cartoon Network series Young Justice voiced by Crispin Freeman. Speedy becomes tired of being treated with low respect and quits being Green Arrow's partner, changing his name to Red Arrow. He is not a founding member of the series' unnamed team of young heroes, and turns down two invitations to join them, but he does consider himself friends with the team's members, and they have made it clear that he has an open invitation should he change his mind. In the first series' finale, it is revealed that Roy had been kidnapped by Lex Luthor and his associates three years prior and cloned to produce a mole, who later became Red Arrow. His unconscious programming led him to aspire to join the Justice League. When he is finally given membership, he allows for Vandal Savage to come aboard the Watchtower and mind control the League. His programming falters after his prime objective is carried out, and he is devastated to learn of his supposed imposter status. In season two, set five years later, Roy has had his child Lian by Cheshire but has become a dishevelled substance user due to his grief over the original Roy. Cheshire and Red Arrow later find the original Roy in stasis, who has had an arm amputated, and reawaken him. The original Roy blames Ollie for not rescuing him from Luthor, and later attempts to get revenge against Luthor using a variety of stolen weapons. He is ultimately unsuccessful, and Luthor buys his own safety by offering Roy a prosthetic robotic arm. The original Roy accepts and takes on the codename Arsenal.

Speedy returns in the Teen Titans Go! episode "The Date" where he is voiced by Scott Menville. In the episode, Robin tries to ask Starfire out on a date to a new restaurant. However, she goes out with Speedy because he had asked her first. To do so, Robin ties up Speedy and poses as him to ruin the date and win over Starfire. However, Speedy manages to escape and poses as Robin to battle Robin (as Speedy). Although Robin defeats Speedy, he felt guilty about his actions and told Starfire the truth. Starfire's reaction went from gentle to violently hitting Robin towards a wall. He later makes a cameo appearance in "Starliar" giving a creeped out expression in reaction to the music Raven began playing at the Titans East Annual Dance Party.